Means for corrugating metal tubing



H. H. BAB COCK MEANS FOR CORRUGATING METAL TUBING July 21, 19336.

3 Sheets-Sheet 1 Filed March 7, 1932 3 Sheets-Sheet 2 Lag H. H. BABCOCK MEANS FOR CORRUGATING METAL TUBING Filed March 7 1932 i 9, k W w j fl fir I u 02W W/ a J Mm July 21, 193$.

July 21, 1936. H. H. BABCOCK MEANS FOR CORRUGATING METAL TUBING 3 Sheets-Sheet 3 Filed March 7, 1932 Patented July 21,1936

I UNITED STATES PATENT! OFFICE 2,048,588 MEANS FOR OORBUGATING METAL TUBING Bishop Cleveland, 0hio, a corporation of Ohio Application March I, 1932, Serial No. 597,200

"scum. (oi. its-1a) in the Hollerith & for Apparatus for corrugating metal tubing, issued September 28, 1886.

The object of the present invention is to improve this apparatus and method, to the end of speed and uniformity for commercial purposes. Further objects and advantages of the instant invention .will appear from the detailed description.

In the drawings':-- I 4 Figure 1 is an elevational view of a machine for practicing the method of the invention; Figure 2 is a plan view of the machine;

Figure 3 is a vertical sectional view through the mold sections and the heads and associated parts of the machine showing the condition of the tube after it has been subjected to initial axial pressure. parts being shown in elevation;

Figure 4 is a-view similar to Figure 3 after the completion of the corrugating operation;

Figure 5 is a face view of one of the mold sec- 23:8 and the holder therefor, on an enlarged Figure 6 is a vertical sectional view through a tube to be corrugated and the associated mold sections, before the tube has been subjected to initial endwise pressure, the movable head and associated parts being shown in elevation, this view also showing the switch for controlling the solenoid circuit.

The machine comprises a suitablestand l provided with a top 2 in the form of a drain pan. An is mounted on a shelf 4 suitably supported at the lower portion of the stand, and

' suitable type, these has drivin D p mounted upon shelf 4. A water tank 1 is mounted upon shelf 4 and water is discharged into this tank from top 2 by means of a suitable drain pipe A U-shaped frame This frame includes abase ill, a fixed head ii at one end of this base and an upright I! at the other end of the base. A cylinder from upright I! and slidabiy receivesa piston M which is provided, at its inner end, with a head I5. Water is delivered from ump 6 to the cylinder and engages into a 'gation.

II and a three-way valve H which a return pipe I! dis- 'l. with thevalve l1 in the of Figure 2, the water from It, througha pipe from the casing of charges into tank full line position pipe I6 is returned through pipe II to the tank 1 I and the piston I4 is not actuated. By turning the valve into the dotted line position of Figure 2,- pipe I6 is connected to cylinder i3 and piston ll from.

head II. A suitable packing "a may be provided in upright I! about piston It.

A tube It, to be corrugated, is disposed between the heads H and, as in Figure of this tube is flanged outwardly, at 20, and is clamped to the adjacent head by means of a mold which is secured to the head by bolts 21 and contacts the base of the flange away from the head. Preferably, packing gaskets 23 are disposed between the flanges and the heads to 20 form a fluid tight and pressure resistant closure therebetween. Each of the mold sections comprises two members Ila adapted to ilt closely about the tube i9, these members being suitably secured ina holder 24 which is formed in two 25 sections hinged together at 25. A swing bolt 26 is pivoted to a lug 21 of one section of the holder slotted lug 28 of the other section of the holder. A wing nut 2! screws upon the bolt 28 and cooperates with lug 28 for securmg the two sections of the holder together. Each section of the holder is provided with a slotted lug 3.. One of these lugs receives a guide bar II which rests upon base l0 and is insertable and removable through a slot 32 in head I l One end of this guide bar rests in a corresponding recess in upright I2, and the other end secured in head ii by means of a pin it, or in any' other suitable manner. fang 30 of the other: section of the holder receives an upper guide 0 bar 34 pivoted at 35. to upright. i2, this bar being normally held in lowered position by a pin" passing through the bar and throughspaced ears 31 projecting from head H and between which the guide bar fits. Each of the members 2hr of the mold sections is provided with a recess 38 concentric with the tube It and corresponding to approximately one-half of the desired corru- Intermediate mold sections 39 are disposed about the tube It in spaced relation to each other and to the sections 2 l These intermediate mold sections are mounted in suitable holders similar to that shown in Figure 5. The mold sections 39 are provided in the opposite faces thereof with recesses or cavities similar to the s5 1 is connected to tank 1 by a pipe 4|. Thedischarge of pump 5 is connected by a pipe42, to

i 63 securedto upright 12.

a bore 43 (Figures 3 and 4) which opens through head ll into the tube IS. A suitable pressure gauge 44 is connected into pipe is provided with a. relief valve 45. -A valve lever 46'is pivoted at one end, at 41, to a bracket 48 carried by valve fitting 49. A weight 50 is pivoted to the lever 46 adjacent the other end thereof and provides a load upon the valve for normally holding the latter closed, this valve being appropriately connected to the lever as by means of a cievis 5| and valve stem 52, the clevis being pivoted at 53 to the lever. The weight depends fromthe leverinto a solenoid 54 suitably mounted on table to this solenoid from any suitable source, by means of the conductors 55 and 56. Normally, the circuit of the solenoid 54 is open and the weight a considerable downward pull upon the weight 50, thereby materially valve 45. Conveniently, a rheostat 51 of suitable type is included in the solenoid circuit and provides means whereby theeifective strength of the solenoid may be varied within considerable limits, thus rendering it possible to vary the loading of the valve above normal'to' suit conditions.

A mercury tube switch 58, of known type, is interposed in conductor or lead 56. This switch is suitably mounted in a carrier 59 pivoted at 50 upon a frame 6| which i'sadjustably mounted, by slot and screw means 62, upon'a bracket Carrier 55 is provided with a depending finger 64 disposed to contact a trip finger 65 pivoted upon an arm 66 adjustably mounted, by slot and a bracket 68 suitably secured tomovable head l5. Finger 65 is normally" held in-upright position bya leaf spring 69 and astop lug 10, the

spring permitting rocking movement of finger 65 in counterclockwise direction as viewed in Figure 6. The switch 58 isnormally in the positionv shown in Figure 6, in which positionit is held by contact of a stop member ll, extending upwardly from carrier59, with an appropriately disposed stop finger. 12 carried by frame 6|. In this position of the switch 58', the circuit of the solenoid is opened. l 3 With the tube l9 properly mounted between the heads H and I 5, as inFigure 6, finger 64 is immediately in advance of the upper end of trip finger 65. With the three-way-valve I 1 in position to by-pas's the water from pump 6 into the tank 1, thecircuit of motor 3 is closed so as to drive both of the pumps. Pump 5 quickly fills the tube with water and the pressure within the tube is built up to that allowed by the loaded valve 45, it being noted that this pressure is not jsufliciently high to cause stretching and outward, bulging of the tube between the mold sec ;tions, though it should be sufiiciently high to prevent objectionable inward collapsing or wrin 'kling of the tube when it is' initially subjected to endwise or axial pressure. turned into position to admit water from pipe 6 into the cylinder I3, thus moving the head I5 amuse 4'2 and this pipe thinning, between the 2. Electrical energy maybe supplied 50 only is effective to load the valve. When the solenoid is energized, however, it exerts increasing the loading of screw means 61, upon tion, the metal of the toward the head II. This subjects the tube II to axial pressure sufiicient to cause a displacement of the metal of the tube. The metal thus displaced will bulge either inwardly or outwardly between the mold sections. Due to the pressure maintained within the.tube;the metalshould, in

the main, bulge outwardly betweenthemold sections, though it may bulge inwardly between certain of the sectionsas shown in Figure 3, which illustrates the first step,- that is, the condition of the tube after it has been subjected to this initial axial pressure. This initial axial compression'of the tube renders available metal for producing the desired corrugations without subjecting the tube' to objectionable stretching or H I mold sections. ately after this initial axial compression of the tube has occurred, finger 65, which moves with the head I5,, trips the mercury tube switch 58 and rocks it in a clockwise direction, as viewed in Figure, 6, into circuit closingposit'ion, in which position it is held b y contact of stop-1| with stop finger 12 of frame 6| This closes the circuit of the solenoid which I v the load on valve 45, resulting in an'immediate and material increase in pressure within' the tube I 9. This increased pressurewithin the tube is not sufliciently great to cause undesirable stretch- "in the tube by. the axial compression thereof.

The increased pressure within the tube is maintained during the continued movement-of head.

i5 toward head H, and the'formation of the outward bulges of the tube between the die secmaterially increases Immeditions, in conjunction'with theredistribution by the internal pressure of the metal displaced by the axial compression of the tube, serves to lock the movable mold sections 39 to the ,tube so that;

as the metal is bulged'outwardly "between these sectionsand the tube is compressed'axially, mold section 2| carried by head l5 and the intermediate mold'sections 39 are moved toward thehead' ll until the mold sections are in 'contact, at

which time the corrugating of thetube is 'completed, as in Figure 4. It is to be particularly noted that the v wardbulges 'from which the corrugations'are formed, is rendered available by theinitial axial compression of. the tube, these bulges not being produced by stretching of the tube between the mold sections.

cordance with the method of the instant" In acinvenmetal, as displaced, is redistributed bysubject-- ing the tube to internal pressure andis formed: between the mold sections into the desired 001',

rug'z'ations. 1 1 By providing automatic means for increasingthe pressure within the tube, after the-tube has been subjected to predetermined axial compresmetal forfonning the initial'out-r and thinning of the metal- 7 tube is displaced by sub-- jecting the tube to axiafcom'pression, and this of the tube and the diameter thereof, and various other factors. The particular pressures best adapted for use with any particular tubing can readily be determined by e p riment.v The pro vision of the rheostat in the circuit of the solenoid provides convenient means whereby the loading effect of this solenoid can be varied to suit conditions.

What is claimed is:-

1. In combination in means for corrugating metal tubing and the like, means for compressing a tube axially, means for maintaining the tube under a constant and predetermined internal pressure during initial axial compression thereof, and means for automatically increasing the pressure within the tube after axial compression thereof has proceeded to a predetermined extent and for maintaining such increased pressure within the tube at a constant value during continued axial compression of the tube- 2. In combination in means for corrugating metal tubing and the like,-two heads disposed to receive between them a tube to be corrugated, the heads closing the ends of the tube, means for imparting relative movement to the heads toward each other for compressing the tube axially, means for subjecting the tube to 'predetermined internal pressure during initial axial compression thereof, and means for automatically increasing the pressure within the tube after predetermined relative movement of the heads toward each other.

3. In combination in means for corrugating metal tubing andthe like, two heads one of which is movable toward, and away from the other,

said heads being disposed to receive between them a tube to be corrugated with its ends closed by and in abutting relation to the heads, means for moving the movable head toward the other head and thereby compressing the tube axially, and means for subjecting the tube to predetermined internal pressure at the initiation of the axial compression thereof and for automatically increasingthe pressure within the tube after axial compression of the latter to a predetermined extent.

4. In combination in means for corrugating metal tubing and the like, two heads one of which is movable toward and away from the other, said heads being disposed to receive between them a tube to be corrugated with its ends closed by and in abutting relation to the heads, means for moving the movable head toward the other head and thereby compressing the tube axially, means for subjecting the tube to predetermined internal pressure at the initiation of the axial compression thereof, and means responsive to travel of the movable head for automatically increasing the pressure within the tube in the travel of the movable head toward said other head.

5. In combination in means for corrugating metal tubing and the like, two heads one of which is movable toward and away from the other, said heads being disposed to receive between them a tube to be corrugated with its ends closed by and in abutting relation to the heads, means for moving the movable head toward the other head and thereby compressing the tube axially,

pressure means for supplying fluid to the interior -of the tube and thereby subjecting the latter to '3 internal pressure, a loaded relief valve for controlling the pressure within the tube and initially set to open at a pressure less than the maximum pressure of said pressure means, and means for automatically increasing the loading oithe valve after the tube has been subjected to predetermined axial compression. I

6. In combination in means for corrugatin'g metal tubing and the like, two heads one of which is movable toward and away from the other, said headsbeing disposed to receive between them a tube to be corrugated with its ends closed by and in' abutting relation to the heads, means} for moving the movable head toward the other head and thereby compressing the tube axially,

a constantly driven pump delivering liquid under pressure to the interior of the tube, a loaded relief valve between the pump and the tube, and initially set to open at a pressure less than the I maximum pressure of said pump, and means for tube to be corrugated with its ends closed by and in abutting relation to the heads, means for moving the movable head toward the-other head and thereby compressing the tube axially, a constantly driven pump delivering liquid to the interior of the tube, a relief valve between the pump and the tube, a lever connected to the valve, a weight on the lever for loading the valve, a solenoid, the weight being subjected to the magnetic field of the solenoid when the latter is energized, and means for automatically closing the circuit of the solenoid after the tube has been subjected to predetermined axial compression.

8. In combination in means for corrugating I metal tubing and the like, two heads one of which is movable toward and away from the other, said heads being disposed to receive between them a tube to be corrugated with its ends closed by and in abutting relation to the heads, means for moving the movable head toward the other head and thereby compressing the tube axially, a constantly driven pumpdelivering liquid to the interior of the tube, a relief valve between the pump and the tube, a lever connected to the valve, a weight on the lever for loading the valve, a solenoid, the weight being subjected to the magnetic field of the solenoid when the latter is energized, and means actuated by the movable head for automatically closing the circuit of the solenoid after the tube has been subjected to predetermined axial compression.

9. In combination in means for 'corrugating metal tubing and the like, two heads one of which is movable toward and away from the other, said heads being disposed to receive between them a tube to be corrugated with its ends closed by and in abutting relation to the heads, means for moving the movable head toward the other head and thereby compressing the tube axially, a constantly driven pump delivering liquid to the interior of the tube, a relief valve between the pump and the tube, a lever connected to the valve, a solenoid, a weight on the lever for load- 

